The Believers - 23:68
Have they not examined the Word, or has something come to them which did not come to their ancestors of the past?
If they had examined it, they would have realized that the Qur'an is the word of Allah:
The Women/4:82
Do they not examine the Qur´an? Had it belonged to anyone other than Allah, they would have found many contradictions in it.
The Cave/18:1
Praise be to Allah, Who has sent down the Book to His servant and has left no crookedness in it.
The Arabic Letter Sad/38:29
Blessed is this Book which We have sent down to you, that they may examine its verses and that those of understanding may take admonition.
Muhammad/47:24
Why do they not search and study the Qur´an? Or are their brains locked?